/*
 * Minio Cloud Storage, (C) 2015, 2016 Minio, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package main

import (
	"bytes"
	"fmt"
	"io/ioutil"
	"net/http"
	"net/http/httptest"
	"testing"
)

// Tests validate Bucket policy resource matcher.
func TestBucketPolicyResourceMatch(t *testing.T) {

	// generates statement with given resource..
	generateStatement := func(resource string) policyStatement {
		statement := policyStatement{}
		statement.Resources = []string{resource}
		return statement
	}

	// generates resource prefix.
	generateResource := func(bucketName, objectName string) string {
		return AWSResourcePrefix + bucketName + "/" + objectName
	}

	testCases := []struct {
		resourceToMatch       string
		statement             policyStatement
		expectedResourceMatch bool
	}{
		// Test case 1-4.
		// Policy with resource ending with bucket/* allows access to all objects inside the given bucket.
		{generateResource("minio-bucket", ""), generateStatement(fmt.Sprintf("%s%s", AWSResourcePrefix, "minio-bucket"+"/*")), true},
		{generateResource("minio-bucket", ""), generateStatement(fmt.Sprintf("%s%s", AWSResourcePrefix, "minio-bucket"+"/*")), true},
		{generateResource("minio-bucket", ""), generateStatement(fmt.Sprintf("%s%s", AWSResourcePrefix, "minio-bucket"+"/*")), true},
		{generateResource("minio-bucket", ""), generateStatement(fmt.Sprintf("%s%s", AWSResourcePrefix, "minio-bucket"+"/*")), true},
		// Test case - 5.
		// Policy with resource ending with bucket/oo* should not allow access to bucket/output.txt.
		{generateResource("minio-bucket", "output.txt"), generateStatement(fmt.Sprintf("%s%s", AWSResourcePrefix, "minio-bucket"+"/oo*")), false},
		// Test case - 6.
		// Policy with resource ending with bucket/oo* should allow access to bucket/ootput.txt.
		{generateResource("minio-bucket", "ootput.txt"), generateStatement(fmt.Sprintf("%s%s", AWSResourcePrefix, "minio-bucket"+"/oo*")), true},
		// Test case - 7.
		// Policy with resource ending with bucket/oo* allows access to all subfolders starting with "oo" inside given bucket.
		{generateResource("minio-bucket", "oop-bucket/my-file"), generateStatement(fmt.Sprintf("%s%s", AWSResourcePrefix, "minio-bucket"+"/oo*")), true},
		// Test case - 8.
		{generateResource("minio-bucket", "Asia/India/1.pjg"), generateStatement(fmt.Sprintf("%s%s", AWSResourcePrefix, "minio-bucket"+"/Asia/Japan/*")), false},
		// Test case - 9.
		{generateResource("minio-bucket", "Asia/India/1.pjg"), generateStatement(fmt.Sprintf("%s%s", AWSResourcePrefix, "minio-bucket"+"/Asia/Japan/*")), false},
		// Test case - 10.
		// Proves that the name space is flat.
		{generateResource("minio-bucket", "Africa/Bihar/India/design_info.doc/Bihar"), generateStatement(fmt.Sprintf("%s%s", AWSResourcePrefix,
			"minio-bucket"+"/*/India/*/Bihar")), true},
		// Test case - 11.
		// Proves that the name space is flat.
		{generateResource("minio-bucket", "Asia/China/India/States/Bihar/output.txt"), generateStatement(fmt.Sprintf("%s%s", AWSResourcePrefix,
			"minio-bucket"+"/*/India/*/Bihar/*")), true},
	}
	for i, testCase := range testCases {
		actualResourceMatch := bucketPolicyResourceMatch(testCase.resourceToMatch, testCase.statement)
		if testCase.expectedResourceMatch != actualResourceMatch {
			t.Errorf("Test %d: Expected Resource match to be `%v`, but instead found it to be `%v`", i+1, testCase.expectedResourceMatch, actualResourceMatch)
		}
	}
}

// TestBucketPolicyActionMatch - Test validates whether given action on the
// bucket/object matches the allowed actions in policyStatement.
// This test preserves the allowed actions for all 3 sets of policies, that is read-write,read-only, write-only.
// The intention of the test is to catch any changes made to allowed action for on eof the above 3 major policy groups mentioned.
func TestBucketPolicyActionMatch(t *testing.T) {
	bucketName := getRandomBucketName()
	objectPrefix := "test-object"

	testCases := []struct {
		action         string
		statement      policyStatement
		expectedResult bool
	}{
		// s3:GetBucketLocation is the action necessary to be present in the bucket policy to allow
		// fetching of bucket location on an Anonymous/unsigned request.

		//r ead-write bucket policy is expected to allow GetBucketLocation operation on an anonymous request (Test case - 1).
		{"s3:GetBucketLocation", getReadWriteBucketStatement(bucketName, objectPrefix), true},
		//	write-only bucket policy is expected to allow GetBucketLocation operation on an anonymous request (Test case - 2).
		{"s3:GetBucketLocation", getWriteOnlyBucketStatement(bucketName, objectPrefix), true},
		//	read-only bucket policy is expected to allow GetBucketLocation operation on an anonymous request (Test case - 3).
		{"s3:GetBucketLocation", getReadOnlyBucketStatement(bucketName, objectPrefix), true},

		// Any of the Object level access permissions shouldn't allow for GetBucketLocation operation  on an Anonymous/unsigned request (Test cases 4-6).
		{"s3:GetBucketLocation", getReadWriteObjectStatement(bucketName, objectPrefix), false},
		{"s3:GetBucketLocation", getWriteOnlyObjectStatement(bucketName, objectPrefix), false},
		{"s3:GetBucketLocation", getReadOnlyObjectStatement(bucketName, objectPrefix), false},

		// s3:ListBucketMultipartUploads is the action necessary to be present in the bucket policy to allow
		// Listing of multipart uploads in a given bucket for an Anonymous/unsigned request.

		//read-write bucket policy is expected to allow  ListBucketMultipartUploads operation on an anonymous request (Test case 7).
		{"s3:ListBucketMultipartUploads", getReadWriteBucketStatement(bucketName, objectPrefix), true},
		//	write-only bucket policy is expected to allow  ListBucketMultipartUploads operation on an anonymous request (Test case 8).
		{"s3:ListBucketMultipartUploads", getWriteOnlyBucketStatement(bucketName, objectPrefix), true},
		// read-only bucket policy is expected to not allow ListBucketMultipartUploads operation on an anonymous request (Test case 9).
		// the allowed actions in read-only bucket statement are  "s3:GetBucketLocation","s3:ListBucket",
		// this shouldnot allow for ListBucketMultipartUploads operations.
		{"s3:ListBucketMultipartUploads", getReadOnlyBucketStatement(bucketName, objectPrefix), false},

		// Any of the object level policy will not allow for s3:ListBucketMultipartUploads (Test cases 10-12).
		{"s3:ListBucketMultipartUploads", getReadWriteObjectStatement(bucketName, objectPrefix), false},
		{"s3:ListBucketMultipartUploads", getWriteOnlyObjectStatement(bucketName, objectPrefix), false},
		{"s3:ListBucketMultipartUploads", getReadOnlyObjectStatement(bucketName, objectPrefix), false},

		// s3:ListBucket is the action necessary to be present in the bucket policy to allow
		// listing of all objects inside a given bucket on an Anonymous/unsigned request.

		// Cases for testing ListBucket access for different Bucket level access permissions.
		// read-only bucket policy is expected to allow ListBucket operation on an anonymous request (Test case 13).
		{"s3:ListBucket", getReadOnlyBucketStatement(bucketName, objectPrefix), true},
		// read-write bucket policy is expected to allow ListBucket operation on an anonymous request (Test case 14).
		{"s3:ListBucket", getReadWriteBucketStatement(bucketName, objectPrefix), true},
		// write-only  bucket policy is expected to not allow ListBucket operation on an anonymous request (Test case 15).
		// the allowed actions in write-only  bucket statement are "s3:GetBucketLocation",	"s3:ListBucketMultipartUploads",
		// this shouldnot allow for ListBucket operations.
		{"s3:ListBucket", getWriteOnlyBucketStatement(bucketName, objectPrefix), false},

		// Cases for testing ListBucket access for different Object level access permissions (Test cases 16-18).
		// Any of the Object level access permissions shouldn't allow for ListBucket operation  on an Anonymous/unsigned request.
		{"s3:ListBucket", getReadOnlyObjectStatement(bucketName, objectPrefix), false},
		{"s3:ListBucket", getReadWriteObjectStatement(bucketName, objectPrefix), false},
		{"s3:ListBucket", getWriteOnlyObjectStatement(bucketName, objectPrefix), false},

		// s3:DeleteObject is the action necessary to be present in the bucket policy to allow
		// deleting/removal of  objects inside a given bucket for an Anonymous/unsigned request.

		// Cases for testing DeleteObject access for different Bucket level access permissions (Test cases 19-21).
		// Any of the Bucket level access permissions shouldn't allow for DeleteObject operation  on an Anonymous/unsigned request.
		{"s3:DeleteObject", getReadOnlyBucketStatement(bucketName, objectPrefix), false},
		{"s3:DeleteObject", getReadWriteBucketStatement(bucketName, objectPrefix), false},
		{"s3:DeleteObject", getWriteOnlyBucketStatement(bucketName, objectPrefix), false},

		// Cases for testing DeleteObject access for different Object level access permissions (Test cases 22).
		// read-only bucket policy is expected to not allow Delete Object operation on an anonymous request.
		{"s3:DeleteObject", getReadOnlyObjectStatement(bucketName, objectPrefix), false},
		// read-write bucket policy is expected to allow Delete Bucket operation on an anonymous request (Test cases 23).
		{"s3:DeleteObject", getReadWriteObjectStatement(bucketName, objectPrefix), true},
		// write-only  bucket policy is expected to allow Delete Object operation on an anonymous request (Test cases 24).
		{"s3:DeleteObject", getWriteOnlyObjectStatement(bucketName, objectPrefix), true},

		// s3:AbortMultipartUpload is the action necessary to be present in the bucket policy to allow
		// cancelling or abortion of an already initiated multipart upload operation for an Anonymous/unsigned request.

		// Cases for testing AbortMultipartUpload access for different Bucket level access permissions (Test cases 25-27).
		// Any of the Bucket level access permissions shouldn't allow for AbortMultipartUpload operation on an Anonymous/unsigned request.
		{"s3:AbortMultipartUpload", getReadOnlyBucketStatement(bucketName, objectPrefix), false},
		{"s3:AbortMultipartUpload", getReadWriteBucketStatement(bucketName, objectPrefix), false},
		{"s3:AbortMultipartUpload", getWriteOnlyBucketStatement(bucketName, objectPrefix), false},

		// Cases for testing AbortMultipartUpload access for different Object level access permissions.
		// read-only object policy is expected to not allow AbortMultipartUpload operation on an anonymous request (Test case 28).
		{"s3:AbortMultipartUpload", getReadOnlyObjectStatement(bucketName, objectPrefix), false},
		// read-write object policy is expected to allow AbortMultipartUpload operation on an anonymous request (Test case 29).
		{"s3:AbortMultipartUpload", getReadWriteObjectStatement(bucketName, objectPrefix), true},
		// write-only object policy is expected to allow AbortMultipartUpload operation on an anonymous request (Test case 30).
		{"s3:AbortMultipartUpload", getWriteOnlyObjectStatement(bucketName, objectPrefix), true},

		// s3:PutObject is the action necessary to be present in the bucket policy to allow
		// uploading of an object for an Anonymous/unsigned request.

		// Cases for testing PutObject access for different Bucket level access permissions (Test cases 31-33).
		// Any of the Bucket level access permissions shouldn't allow for PutObject operation on an Anonymous/unsigned request.
		{"s3:PutObject", getReadOnlyBucketStatement(bucketName, objectPrefix), false},
		{"s3:PutObject", getReadWriteBucketStatement(bucketName, objectPrefix), false},
		{"s3:PutObject", getWriteOnlyBucketStatement(bucketName, objectPrefix), false},

		// Cases for testing PutObject access for different Object level access permissions.
		// read-only object policy is expected to not allow PutObject operation on an anonymous request (Test case 34).
		{"s3:PutObject", getReadOnlyObjectStatement(bucketName, objectPrefix), false},
		// read-write object policy is expected to allow PutObject operation on an anonymous request (Test case 35).
		{"s3:PutObject", getReadWriteObjectStatement(bucketName, objectPrefix), true},
		// write-only  object policy is expected to allow PutObject operation on an anonymous request (Test case 36).
		{"s3:PutObject", getWriteOnlyObjectStatement(bucketName, objectPrefix), true},

		// s3:GetObject is the action necessary to be present in the bucket policy to allow
		// downloading of an object for an Anonymous/unsigned request.

		// Cases for testing GetObject access for different Bucket level access permissions (Test cases 37-39).
		// Any of the Bucket level access permissions shouldn't allow for GetObject operation on an Anonymous/unsigned request.
		{"s3:GetObject", getReadOnlyBucketStatement(bucketName, objectPrefix), false},
		{"s3:GetObject", getReadWriteBucketStatement(bucketName, objectPrefix), false},
		{"s3:GetObject", getWriteOnlyBucketStatement(bucketName, objectPrefix), false},

		// Cases for testing GetObject access for different Object level access permissions.
		// read-only bucket policy is expected to allow  downloading of an Object on an anonymous request (Test case 40).
		{"s3:GetObject", getReadOnlyObjectStatement(bucketName, objectPrefix), true},
		// read-write bucket policy is expected to allow  downloading of an Object on an anonymous request (Test case 41).
		{"s3:GetObject", getReadWriteObjectStatement(bucketName, objectPrefix), true},
		// write-only  bucket policy is expected to not allow  downloading of an Object on an anonymous request (Test case 42).
		{"s3:GetObject", getWriteOnlyObjectStatement(bucketName, objectPrefix), false},

		// s3:ListMultipartUploadParts is the action necessary to be present in the bucket policy to allow
		// Listing of uploaded parts for an Anonymous/unsigned request.

		// Any of the Bucket level access permissions shouldn't allow for ListMultipartUploadParts operation on an Anonymous/unsigned request.
		// read-only bucket policy is expected to not allow ListMultipartUploadParts operation on an anonymous request (Test cases 43-45).
		{"s3:ListMultipartUploadParts", getReadOnlyBucketStatement(bucketName, objectPrefix), false},
		{"s3:ListMultipartUploadParts", getReadWriteBucketStatement(bucketName, objectPrefix), false},
		{"s3:ListMultipartUploadParts", getWriteOnlyBucketStatement(bucketName, objectPrefix), false},

		// read-only object policy is expected to not allow ListMultipartUploadParts operation on an anonymous request (Test case 46).
		{"s3:ListMultipartUploadParts", getReadOnlyObjectStatement(bucketName, objectPrefix), false},
		// read-write object policy is expected to allow ListMultipartUploadParts operation on an anonymous request (Test case 47).
		{"s3:ListMultipartUploadParts", getReadWriteObjectStatement(bucketName, objectPrefix), true},
		// write-only  object policy is expected to allow ListMultipartUploadParts operation on an anonymous request (Test case 48).
		{"s3:ListMultipartUploadParts", getWriteOnlyObjectStatement(bucketName, objectPrefix), true},
	}
	for i, testCase := range testCases {
		actualResult := bucketPolicyActionMatch(testCase.action, testCase.statement)
		if testCase.expectedResult != actualResult {
			t.Errorf("Test %d: Expected the result to be `%v`, but instead found it to be `%v`", i+1, testCase.expectedResult, actualResult)
		}
	}
}

// TestWildCardMatch - Tests validate the logic of wild card matching.
// Its used to match the action and resources of the policy statement and the request.
func TestWildCardMatch(t *testing.T) {
	testCases := []struct {
		pattern        string
		text           string
		expectedResult bool
	}{
		// Test case - 1.
		// Test case with pattern "*". Expected to match any text.
		{"*", "s3:GetObject", true},
		// Test case - 2.
		// Test case with empty pattern. This only matches empty string.
		{"", "s3:GetObject", false},
		// Test case - 3.
		// Test case with empty pattern. This only matches empty string.
		{"", "", true},
		// Test case - 4.
		// Test case with single "*" at the end.
		{"s3:*", "s3:ListMultipartUploadParts", true},
		// Test case - 5.
		// Test case with a no "*". In this case the pattern and text should be the same.
		{"s3:ListBucketMultipartUploads", "s3:ListBucket", false},
		// Test case - 6.
		// Test case with a no "*". In this case the pattern and text should be the same.
		{"s3:ListBucket", "s3:ListBucket", true},
		// Test case - 7.
		// Test case with a no "*". In this case the pattern and text should be the same.
		{"s3:ListBucketMultipartUploads", "s3:ListBucketMultipartUploads", true},
		// Test case - 8.
		// Test case with pattern containing key name with a prefix. Should accept the same text without a "*".
		{"my-bucket/oo*", "my-bucket/oo", true},
		// Test case - 9.
		// Test case with "*" at the end of the pattern.
		{"my-bucket/In*", "my-bucket/India/Karnataka/", true},
		// Test case - 10.
		// Test case with prefixes shuffled.
		// This should fail.
		{"my-bucket/In*", "my-bucket/Karnataka/India/", false},
		// Test case - 11.
		// Test case with text expanded to the wildcards in the pattern.
		{"my-bucket/In*/Ka*/Ban", "my-bucket/India/Karnataka/Ban", true},
		// Test case - 12.
		// Test case with the  keyname part is repeated as prefix several times.
		// This is valid.
		{"my-bucket/In*/Ka*/Ban", "my-bucket/India/Karnataka/Ban/Ban/Ban/Ban/Ban", true},
		// Test case - 13.
		// Test case to validate that `*` can be expanded into multiple prefixes.
		{"my-bucket/In*/Ka*/Ban", "my-bucket/India/Karnataka/Area1/Area2/Area3/Ban", true},
		// Test case to validate that `*` can be expanded into multiple prefixes.
		{"my-bucket/In*/Ka*/Ban", "my-bucket/India/State1/State2/Karnataka/Area1/Area2/Area3/Ban", true},
		// Test case - 14.
		// Test case where the keyname part of the pattern is expanded in the text.
		{"my-bucket/In*/Ka*/Ban", "my-bucket/India/Karnataka/Bangalore", false},
		// Test case - 15.
		// Test case with prefixes and wildcard expanded for all "*".
		{"my-bucket/In*/Ka*/Ban*", "my-bucket/India/Karnataka/Bangalore", true},
		// Test case - 16.
		// Test case with keyname part being a wildcard in the pattern.
		{"my-bucket/*", "my-bucket/India", true},
		// Test case - 17.
		{"my-bucket/oo*", "my-bucket/odo", false},
	}
	// Iterating over the test cases, call the function under test and asert the output.
	for i, testCase := range testCases {
		actualResult := wildCardMatch(testCase.pattern, testCase.text)
		if testCase.expectedResult != actualResult {
			t.Errorf("Test %d: Expected the result to be `%v`, but instead found it to be `%v`", i+1, testCase.expectedResult, actualResult)
		}
	}
}

// Wrapper for calling Put Bucket Policy HTTP handler tests for both XL multiple disks and single node setup.
func TestPutBucketPolicyHandler(t *testing.T) {
	ExecObjectLayerTest(t, testPutBucketPolicyHandler)
}

// testPutBucketPolicyHandler - Test for Bucket policy end point.
// TODO: Add exhaustive cases with various combination of statement fields.
func testPutBucketPolicyHandler(obj ObjectLayer, instanceType string, t TestErrHandler) {
	// get random bucket name.
	bucketName := getRandomBucketName()
	// Create bucket.
	err := obj.MakeBucket(bucketName)
	if err != nil {
		// failed to create newbucket, abort.
		t.Fatalf("%s : %s", instanceType, err)
	}
	// Register the API end points with XL/FS object layer.
	apiRouter := initTestAPIEndPoints(obj, []string{"PutBucketPolicy"})
	// initialize the server and obtain the credentials and root.
	// credentials are necessary to sign the HTTP request.
	rootPath, err := newTestConfig("us-east-1")
	if err != nil {
		t.Fatalf("Init Test config failed")
	}
	// remove the root folder after the test ends.
	defer removeAll(rootPath)

	credentials := serverConfig.GetCredential()

	// template for constructing HTTP request body for PUT bucket policy.
	bucketPolicyTemplate := `{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Action": [
                "s3:GetBucketLocation",
                "s3:ListBucket"
            ],
            "Effect": "Allow",
            "Principal": {
                "AWS": [
                    "*"
                ]
            },
            "Resource": [
                "arn:aws:s3:::%s"
            ]
        },
        {
            "Action": [
                "s3:GetObject"
            ],
            "Effect": "Allow",
            "Principal": {
                "AWS": [
                    "*"
                ]
            },
            "Resource": [
                "arn:aws:s3:::%s/this*"
            ]
        }
    ]
}`

	// test cases with sample input and expected output.
	testCases := []struct {
		bucketName string
		accessKey  string
		secretKey  string
		// expected Response.
		expectedRespStatus int
	}{
		{bucketName, credentials.AccessKeyID, credentials.SecretAccessKey, http.StatusNoContent},
	}

	// Iterating over the test cases, calling the function under test and asserting the response.
	for i, testCase := range testCases {
		// obtain the put bucket policy request body.
		bucketPolicyStr := fmt.Sprintf(bucketPolicyTemplate, testCase.bucketName, testCase.bucketName)
		// initialize HTTP NewRecorder, this records any mutations to response writer inside the handler.
		rec := httptest.NewRecorder()
		// construct HTTP request for PUT bucket policy endpoint.
		req, err := newTestSignedRequest("PUT", getPutPolicyURL("", testCase.bucketName),
			int64(len(bucketPolicyStr)), bytes.NewReader([]byte(bucketPolicyStr)), testCase.accessKey, testCase.secretKey)
		if err != nil {
			t.Fatalf("Test %d: Failed to create HTTP request for PutBucketPolicyHandler: <ERROR> %v", i+1, err)
		}
		// Since `apiRouter` satisfies `http.Handler` it has a ServeHTTP to execute the logic ofthe handler.
		// Call the ServeHTTP to execute the handler.
		apiRouter.ServeHTTP(rec, req)
		if rec.Code != testCase.expectedRespStatus {
			t.Errorf("Test %d: Expected the response status to be `%d`, but instead found `%d`", i+1, testCase.expectedRespStatus, rec.Code)
		}
	}
}

// Wrapper for calling Get Bucket Policy HTTP handler tests for both XL multiple disks and single node setup.
func TestGetBucketPolicyHandler(t *testing.T) {
	ExecObjectLayerTest(t, testGetBucketPolicyHandler)
}

// testGetBucketPolicyHandler - Test for end point which fetches the access policy json of the given bucket.
// TODO: Add exhaustive cases with various combination of statement fields.
func testGetBucketPolicyHandler(obj ObjectLayer, instanceType string, t TestErrHandler) {
	// get random bucket name.
	bucketName := getRandomBucketName()
	// Create bucket.
	err := obj.MakeBucket(bucketName)
	if err != nil {
		// failed to create newbucket, abort.
		t.Fatalf("%s : %s", instanceType, err)
	}
	// Register the API end points with XL/FS object layer.
	// Registering only the PutBucketPolicy and GetBucketPolicy handlers.
	apiRouter := initTestAPIEndPoints(obj, []string{"PutBucketPolicy", "GetBucketPolicy"})
	// initialize the server and obtain the credentials and root.
	// credentials are necessary to sign the HTTP request.
	rootPath, err := newTestConfig("us-east-1")
	if err != nil {
		t.Fatalf("Init Test config failed")
	}
	// remove the root folder after the test ends.
	defer removeAll(rootPath)

	credentials := serverConfig.GetCredential()

	// template for constructing HTTP request body for PUT bucket policy.
	bucketPolicyTemplate := `{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Action": [
                "s3:GetBucketLocation",
                "s3:ListBucket"
            ],
            "Effect": "Allow",
            "Principal": {
                "AWS": [
                    "*"
                ]
            },
            "Resource": [
                "arn:aws:s3:::%s"
            ]
        },
        {
            "Action": [
                "s3:GetObject"
            ],
            "Effect": "Allow",
            "Principal": {
                "AWS": [
                    "*"
                ]
            },
            "Resource": [
                "arn:aws:s3:::%s/this*"
            ]
        }
    ]
}`

	// Writing bucket policy before running test on GetBucketPolicy.
	putTestPolicies := []struct {
		bucketName string
		accessKey  string
		secretKey  string
		// expected Response.
		expectedRespStatus int
	}{
		{bucketName, credentials.AccessKeyID, credentials.SecretAccessKey, http.StatusNoContent},
	}

	// Iterating over the cases and writing the bucket policy.
	// its required to write the policies first before running tests on GetBucketPolicy.
	for i, testPolicy := range putTestPolicies {
		// obtain the put bucket policy request body.
		bucketPolicyStr := fmt.Sprintf(bucketPolicyTemplate, testPolicy.bucketName, testPolicy.bucketName)
		// initialize HTTP NewRecorder, this records any mutations to response writer inside the handler.
		rec := httptest.NewRecorder()
		// construct HTTP request for PUT bucket policy endpoint.
		req, err := newTestSignedRequest("PUT", getPutPolicyURL("", testPolicy.bucketName),
			int64(len(bucketPolicyStr)), bytes.NewReader([]byte(bucketPolicyStr)), testPolicy.accessKey, testPolicy.secretKey)
		if err != nil {
			t.Fatalf("Test %d: Failed to create HTTP request for PutBucketPolicyHandler: <ERROR> %v", i+1, err)
		}
		// Since `apiRouter` satisfies `http.Handler` it has a ServeHTTP to execute the logic ofthe handler.
		// Call the ServeHTTP to execute the handler.
		apiRouter.ServeHTTP(rec, req)
		if rec.Code != testPolicy.expectedRespStatus {
			t.Fatalf("Case %d: Expected the response status to be `%d`, but instead found `%d`", i+1, testPolicy.expectedRespStatus, rec.Code)
		}
	}

	// test cases with inputs and expected result for GetBucketPolicyHandler.
	testCases := []struct {
		bucketName string
		accessKey  string
		secretKey  string
		// expected output.
		expectedBucketPolicy string
		expectedRespStatus   int
	}{
		{bucketName, credentials.AccessKeyID, credentials.SecretAccessKey, bucketPolicyTemplate, http.StatusOK},
	}
	// Iterating over the cases, fetching the policy and validating the response.
	for i, testCase := range testCases {
		// expected bucket policy json string.
		expectedBucketPolicyStr := fmt.Sprintf(testCase.expectedBucketPolicy, testCase.bucketName, testCase.bucketName)
		// initialize HTTP NewRecorder, this records any mutations to response writer inside the handler.
		rec := httptest.NewRecorder()
		// construct HTTP request for PUT bucket policy endpoint.
		req, err := newTestSignedRequest("GET", getGetPolicyURL("", testCase.bucketName),
			0, nil, testCase.accessKey, testCase.secretKey)

		if err != nil {
			t.Fatalf("Test %d: Failed to create HTTP request for GetBucketPolicyHandler: <ERROR> %v", i+1, err)
		}
		// Since `apiRouter` satisfies `http.Handler` it has a ServeHTTP to execute the logic of the handler.
		// Call the ServeHTTP to execute the handler, GetBucketPolicyHandler handles the request.
		apiRouter.ServeHTTP(rec, req)
		// Assert the response code with the expected status.
		if rec.Code != testCase.expectedRespStatus {
			t.Fatalf("Case %d: Expected the response status to be `%d`, but instead found `%d`", i+1, testCase.expectedRespStatus, rec.Code)
		}
		// read the response body.
		bucketPolicyReadBuf, err := ioutil.ReadAll(rec.Body)
		if err != nil {
			t.Fatalf("Test %d: %s: Failed parsing response body: <ERROR> %v", i+1, instanceType, err)
		}
		// Verify whether the bucket policy fetched is same as the one inserted.
		if expectedBucketPolicyStr != string(bucketPolicyReadBuf) {
			t.Errorf("Test %d: %s: Bucket policy differs from expected value.", i+1, instanceType)
		}
	}
}

// Wrapper for calling Delete Bucket Policy HTTP handler tests for both XL multiple disks and single node setup.
func TestDeleteBucketPolicyHandler(t *testing.T) {
	ExecObjectLayerTest(t, testDeleteBucketPolicyHandler)
}

// testDeleteBucketPolicyHandler - Test for Delete bucket policy end point.
// TODO: Add exhaustive cases with various combination of statement fields.
func testDeleteBucketPolicyHandler(obj ObjectLayer, instanceType string, t TestErrHandler) {
	// get random bucket name.
	bucketName := getRandomBucketName()
	// Create bucket.
	err := obj.MakeBucket(bucketName)
	if err != nil {
		// failed to create newbucket, abort.
		t.Fatalf("%s : %s", instanceType, err)
	}

	// Register the API end points with XL/FS object layer.
	// Registering PutBucketPolicy and DeleteBucketPolicy handlers.
	apiRouter := initTestAPIEndPoints(obj, []string{"PutBucketPolicy", "DeleteBucketPolicy"})

	// initialize the server and obtain the credentials and root.
	// credentials are necessary to sign the HTTP request.
	rootPath, err := newTestConfig("us-east-1")
	if err != nil {
		t.Fatalf("Init Test config failed")
	}
	// remove the root folder after the test ends.
	defer removeAll(rootPath)

	credentials := serverConfig.GetCredential()

	// template for constructing HTTP request body for PUT bucket policy.
	bucketPolicyTemplate := `{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Action": [
                "s3:GetBucketLocation",
                "s3:ListBucket"
            ],
            "Effect": "Allow",
            "Principal": {
                "AWS": [
                    "*"
                ]
            },
            "Resource": [
                "arn:aws:s3:::%s"
            ]
        },
        {
            "Action": [
                "s3:GetObject"
            ],
            "Effect": "Allow",
            "Principal": {
                "AWS": [
                    "*"
                ]
            },
            "Resource": [
                "arn:aws:s3:::%s/this*"
            ]
        }
    ]
}`

	// Writing bucket policy before running test on DeleteBucketPolicy.
	putTestPolicies := []struct {
		bucketName string
		accessKey  string
		secretKey  string
		// expected Response.
		expectedRespStatus int
	}{
		{bucketName, credentials.AccessKeyID, credentials.SecretAccessKey, http.StatusNoContent},
	}

	// Iterating over the cases and writing the bucket policy.
	// its required to write the policies first before running tests on GetBucketPolicy.
	for i, testPolicy := range putTestPolicies {
		// obtain the put bucket policy request body.
		bucketPolicyStr := fmt.Sprintf(bucketPolicyTemplate, testPolicy.bucketName, testPolicy.bucketName)
		// initialize HTTP NewRecorder, this records any mutations to response writer inside the handler.
		rec := httptest.NewRecorder()
		// construct HTTP request for PUT bucket policy endpoint.
		req, err := newTestSignedRequest("PUT", getPutPolicyURL("", testPolicy.bucketName),
			int64(len(bucketPolicyStr)), bytes.NewReader([]byte(bucketPolicyStr)), testPolicy.accessKey, testPolicy.secretKey)
		if err != nil {
			t.Fatalf("Test %d: Failed to create HTTP request for PutBucketPolicyHandler: <ERROR> %v", i+1, err)
		}
		// Since `apiRouter` satisfies `http.Handler` it has a ServeHTTP to execute the logic of the handler.
		// Call the ServeHTTP to execute the handler.
		apiRouter.ServeHTTP(rec, req)
		if rec.Code != testPolicy.expectedRespStatus {
			t.Fatalf("Case %d: Expected the response status to be `%d`, but instead found `%d`", i+1, testPolicy.expectedRespStatus, rec.Code)
		}
	}
	// testcases with input and expected output for DeleteBucketPolicyHandler.
	testCases := []struct {
		bucketName string
		accessKey  string
		secretKey  string
		// expected Response.
		expectedRespStatus int
	}{
		{bucketName, credentials.AccessKeyID, credentials.SecretAccessKey, http.StatusNoContent},
	}
	// Iterating over the cases and deleting the bucket policy and then asserting response.
	for i, testCase := range testCases {
		// initialize HTTP NewRecorder, this records any mutations to response writer inside the handler.
		rec := httptest.NewRecorder()
		// construct HTTP request for Delete bucket policy endpoint.
		req, err := newTestSignedRequest("DELETE", getDeletePolicyURL("", testCase.bucketName),
			0, nil, testCase.accessKey, testCase.secretKey)

		if err != nil {
			t.Fatalf("Test %d: Failed to create HTTP request for GetBucketPolicyHandler: <ERROR> %v", i+1, err)
		}
		// Since `apiRouter` satisfies `http.Handler` it has a ServeHTTP to execute the logic of the handler.
		// Call the ServeHTTP to execute the handler, DeleteBucketPolicyHandler  handles the request.
		apiRouter.ServeHTTP(rec, req)
		// Assert the response code with the expected status.
		if rec.Code != testCase.expectedRespStatus {
			t.Fatalf("Case %d: Expected the response status to be `%d`, but instead found `%d`", i+1, testCase.expectedRespStatus, rec.Code)
		}

	}
}